#lang racket
(require rackunit)
(require rackunit/text-ui)
(require "3.rkt")

(check-equal? (rember 2 '(1 2 3)) '(1 3) "remove 2 from list") 
(check-equal? (firsts '((1 1 1) (2 2 2) (3 3 3))) '(1 2 3) "return list of firsts") 